Bias tires

FIGURE 26.27 Side force coefficient as function of c (Equation 26.17c) for a bias tire for different loads. The solid line is the function of the brush model. (From Schallamach, A. and Grosch, K.A., Mechanics of Pneumatic Tires, S.K. Clark (ed.), The US Department of Transportation, National Highway Safety Administration, Washington DV, data from Nordeen, D.L. and Cortese, A.D., Trans S.A.E., 72, 325, 1964.)... 

The effect can be seen in Figure 26.75 which shows the results obtained with the two-wheeled trailer discussed above. Tire group A was a re-treaded bias tire group B a commercial steel-belted radial ply tire. When one tire of each group was mounted on the axle of the trailer for equal set slip angles, the direction of the tow bar adjusted itself in such a way that the tires run under the same... 

FIGURE 26.75 Comparing the rate of wear of a retread bias tire with a commercial radial ply tire (a) one tire each mounted on the trailer axle (equal force comparison) and (b) two tires of each group mounted and run consecutively (equal slip). 

S. Bandyopadhyay, N. Mandal, S.L. Agrawal, S. Dasgupta, R. Mukhopadhyay, A.S. Deuri, and S.C. Ameta, Effect of regenerated carbon-black on a bias tire tread cap compound. Progress in Rubber, Plastics and Recycling Technology, 22(3), 195, 2006. 

Bias tires have an even number of plies with cords at an angle of 30-38° from the tread center line. Passenger-car bias tires commonly have two or four plies, with six for heavy duty service. Truck tires are often built with six to twelve plies, although the larger earthmover types may contain thirty or more. 

Natural rubber usage has increased substantially in modern radial tires. Bernard et al. (1985) compared the natural rubber levels of heavy-duty radial truck tires to those of the equivalent bias tire and noted the following increase ... 

Tire construction n. The geometry of the various layers of tire fabric in the final tire. Three constructions are commonly used. Bias Tire - In this construction, tire fabric is laid alternately at bias angles of 25°-400° to the tread direction. An even number of layers (or piles) is used. Radial tire - In a radial tire, tire fabric traverses the body of the tire at 90° to the tread... 

G. Karami, H. Zohari, and E. Setoudeh, Stress Disribution Change in Bias Tires Due to Changes in Cord Angle-A Finite Element Analysis Kautsh. Gummi Kunstst. 51, 450-454 (1998). 

The latter uses an average of 2.34 kg of natural and 3.61 kg of synthetic rubber compared to 0.70 and 4.08 for bias tires (43). Radial truck tires, which are just now growing in importance, use an even larger ratio of natural to synthetic rubber. The net result is that natural rubber production and consumption have continued to grow more than 2% per year over the last decade. Production is now estimated to grow about 1.5% per year while consumption is expected to increase to 3%, leading to possible shortages. However, eastern European countries are currently... 

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